In adults a heart beat of > 100 is considered a tachycardia, in young age group I think the cut-off level depends on age.

Hazim Al Dilaimy Tachycardia is high heart rate (from Greek - fast heart). The normal heart rate is 60 - 80 bpm in adults (can be almost double in newborns and decreases with age). However on ECG recordings tachycardia is usually considered to be present with heart rates over 100 bpm.

Normal heart rate (sinus rhythm) varies between 60 and 100 per minute. Tachycardia is usually defined as heart rate mote than 100 in an adult of older child. The definition should take age also into consideration. In a new born, resting heart rate tends to ne faster and only heart rates exceeding 160 beats per minute come in the category of tachycardia. Similarly in elderly people, heart rates exceeding 90 per minute are normally unusual.

Tachycardia is a fast or irregular heart rhythm, usually more than 100 beats per minute and as many as 400 beats per minute. At these elevated rates, the heart is not able to efficiently pump oxygen-rich blood to your body.

Tachycardia refers to a fast resting heart rate, usually over 100 beats per minute. Tachycardia can be dangerous, depending on its underlying cause and on how hard the heart has to work. Some people with tachycardia may have no symptoms or complications

Оver 100 beats per minute

Heart rate more then 100 bpmin is tachycardia